Belt testing apparatus



July 15, 1952 J. l.. WADDELI.

BELT TESTING APPARATUS Filed June 29, 1949 Patented July 15, 1952 BELT TESTING APBARATUS'A- Y q I n 'Application June 29, l

This invention relates to belt testing apparatus and is especially useful in determining noisy operation and slippage offV-belts.

In the use of belts of small cross-section such as V-belts used for driving the generators and fans of automobiles or for driving light machinery, it has been found that considerable slippage of the belts takes place with fluctuation in load and velocity. Such slippage is evidenced by generation of noise or squeal during operation.

In the manufacture of such belts it is desirable to compare belts of diiferent constructions as to noise generation under conditions simulating conditions encountered during use of the belts while at the same time confining use of the belt to the laboratory where temperature and other conditions may be maintained constant and the belts being tested may be inspected readily.

Objects of the present invention are to provide for testing of belts under conditions simulating conditions under which they are to be used, to provide for testing the belts for noise or squeal generation under fluctuating load or velocity conditions, to provide predetermined fluctuations of speed, to provide for limbering the belt at high speed prior to subjecting it to fluctuating slow speed conditions, and to provide for quick shifting of adjustment from constant speed to fluctuating speed conditions.

These and other objects will appear from the following description and the accompanying drawing. n

The drawing is a perspective view of apparatus constructed in accordance with and embodying the invention.

Referring to the drawing, the numeral IIJ designates a base plate which supports in axial alignment with each other bearings Il, I2, I3, i4 in which a pair of shafts I5, IS are mounted for free rotation in spaced apart relation. A clutch member I1 is fixed to the end of shaft I6 and a cooperating clutch member I8 is slideably mounted and keyed to shaft I5. The arrangement is such that by engaging the clutch members shafts I and IS may be rotated in unison and by disengaging them the shafts may be rotated independently.

An electric motor Zll is adjustably mounted on the bed plate I9 and has a grooved pulley 2| fixed to its shaft. An electric generator 22 is mounted on a pedestal 23 secured to the bed plate Ill. It has a grooved pulley 24 fixed to its shaft. A third grooved pulley 25 is fixed to shaft I5. Pulleys 2|, 24 and 25 are in the same 3 Claims.

plane and provide 'fa triangular arrangement simulating., the arrangement of generator, fan, and cam shaft pulleys of an automobile fan-belt, drive.' A lbelt 26 to be tested is mounted about` these threev` pulleys and with thek clutch member I 8 disengaged the belt 26 may be driven' by motor 2D at a uniform velocity equal to that of an automobile engine running at high speed. The generator 22 may be used to load the drive or current therefrom may be utilized to measure the work performed by the belt. The portion of the apparatus heretofore described may be used for testing the belt at constant speed or for limbering the belt prior to testing it at slower iiuctuating speed.

For driving the belt 26 at a lower fluctuating speed for observing squeal of the belt, an electric motor 33 is adjustably mounted on the bed plate Il?. Its shaft has a grooved pulley 3l xed thereto. A countershaft 32 is rotatably mounted on a tension lever 33 pivotally mounted on the bed plate I0. The lever may be adjusted by a screw 32a to tension the belts. A grooved pulley 34 is xed to shaft 32 and is driven from pulley 3| by a belt 35. A second countershaft 31 is rotatably mounted in bearings 38, 39 on bed plate I0. Shaft 31 is parallel to shafts I6 and 32 and is driven from shaft 32 through a grooved pulley 4Q fixed to shaft 32, a belt 4I, and a pulley 42 fixed to shaft 31.

Shafts 31 and I5 are geared together by a pair of elliptical gears 43, 44 fixed respectively thereto and meshing with each other. The arrangement is such that motor 30 running at uniform speed drives shaft IB at a regularly uctuating speed, which, when clutch member I8 is engaged with clutch member I1, drives shaft I5, pulley 25 and the belt 26 at fluctuating speed. During such operation, motor 2B is deenergized and. merely acts as an idler.

In operation, a belt 26 to be tested is placed on pulleys 2I, 24 and 25. Clutch members I1, IB are disengaged, and motor 20 is energized to drive the belt at a constant high speed comparable with its speed when mounted on an automobile or other drive. After the belt has been tested at uniform speed or is limbered properly, motor 2i) is deenergized and clutch members I1, I8 are engaged. Motorv30 is then energized and drives belt 26 at a slower and iiuctuating speed. The inertia of the drive is such as to cause some slippage of the belt as the speed uctuates permitting the operator to observe any tendency of the belt to squeal during use.

Variations may be made Without departing from the scope of the invention as it is defined by the following claims.

I claim:

1. Apparatus for testing belts, said apparatus comprising a set of pulleys in triangular arrangement for engaging a belt to be tested, drive means fordriying one of said Ipulleys, and; gearing betwellaid 'drive means aridisaidzpulley for cyclically fluctuating the speed of said pulley, said gearing comprising a pair of elliptical gears meshing with each other. Y v y 2. Apparatus for testing belts under-af variety` of speed conditions, said apparatusbgmprising a set of pulleys for supporting-trieben.' in ag.guilty-' ning disposition thereon, means for driving'one of said pulleys at a uniform speed while the belt` is thus supported on said pulleys,L -meansfor' driving another of said pulleys at iiuetuatingv 3. Apparatus for., testingL belts under a variety `by the last said driving means.

JOSEPH L. WADDELL.

REEERENCES CITED ..Tlieffollowing-references are of record in the .'la of; thispatent:

UNITED sTATEs PATENTS Number Name Date 1.749.297 Norman Mar. 4, 1930 v1,954,483 Krall g 1--- Apr. 10, 1934 FOREIGN `PATENTS Number vCountry Date .6915545 Germany "May 30;*1940 

